The Department of Agriculture is evaluating oaten hay varieties for Western Australia to support the State’s growers which produce half a million tonnes for export, on farm use and domestic trading.

The Department’s research with the South Australian Research and Development Institute was presented at the Agribusiness Crop Updates and at the Northam Crop Updates last month.

Research agronomist Tom Sweeny said six variety trials were sown in 2003 at Katanning, Beverley, Williams, Narrogin, York and Wongan Hills to evaluate 28 varieties and eight breeding lines.

Mr Sweeny said the common varieties sown at all sites were Carrolup, Swan, Vasse, Wandering, Winjardie and Wintaroo.

Plots were sampled at the early milk stage to determine hay yield and sub-samples were milled and analysed for hay quality.

“Hay yields of the milling variety Carrolup and feed variety Wandering were similar to the best hay varieties – Swan, Eurabbie, Brusher and Wintaroo,” he said.

“The milling variety Carrolup is accepted by most export hay companies because it has a thin stem, but the new hay variety Wintaroo has the advantage of not browning off with hot, dry winds and has a darker leaf colour.  Wintaroo is a high quality, purpose-bred hay variety.”

Mr Sweeny said the research highlighted the importance of cutting time. Earlier cutting led to increased water soluble carbohydrates, increased digestibility and decreased neutral detergent fibre. 

“Cutting time and management usually occurs in October.  Hay yield and quality are maximised when it is cut around the early milk stage.  Varieties with good colour like Wintaroo need to be monitored carefully, to make sure that they are cut at the right stage.

“It is a good idea to sow different varieties to spread out the cutting time.”

He said additional agronomic research trials were conducted at four locations at Calingiri, Meckering, Narrogin and Katanning to examine the relationship between nutrition on hay yield and hay quality. 

One trial series evaluated the influence of phosphorus supply and another the influence of nitrogen interactions with potassium supply.

“Hay yields of 10 tonnes per hectare were recorded at all sites except Narrogin,” Mr Sweeny said. 

“There was significant variability in hay yield at each site with variation between 10 and 20 per cent. 

“Across the sites, hay yields of Esk, Glider, Marloo, Massif, Vasse and Wallaroo were generally inferior to the other varieties. 

“Hay yields of Bettong, Eurabie, Swan, Wandering, Winjardie were similar to the milling variety Carrolup and the new hay varieties Brusher and Wintaroo.” 

Of the breeding lines evaluated, four had similar hay yields to Brusher, Carrolup, Wandering and Wintaroo.  The most advanced hay breeding line was a tall mid-late season line scheduled for release in 2005.